This section provides information related to the present disclosure which is not necessarily prior art.
A large number of luminaires in vehicles are known from the prior art. Various illumination units with different functions are attached both in the interior and to the outer contour of the vehicle.
In the interior, lamps for instruments and specific vehicle regions are present to provide illumination for the identification of operating elements or as lamps for reading or for ambient illumination. In order to provide a pleasant environment, regions such as the foot space, the armrest at the vehicle doors, operating elements, interior mirror or roof modules are illuminated at least when entering and exiting the vehicle.
Outside of the vehicle, lamps serve for marking in the form of a position lamp, as front or rear illumination, or as a flashing indicator of lane change or as a warning indicator for the driver.
Lamps need to meet specific requirements both inside and outside. First, the ability to meet regulations that define for example the luminance and indicator flash rates should be noted here. The spatial regions that are to be illuminated in the vicinity of the vehicle are likewise governed by regulations. In addition to licence conditions, the function and the design determine the appearance of the lamp.
An important parameter in the prior art is here that the lamp is attached such that it is concealed. That means that the cover plate that terminates the illumination unit towards the outside is matched to the environment in terms of colour shade or is tinted dark so as not to be noticeable.
In addition, the cover plate is intended to prevent a clear view of the technical components inside the illumination unit.
Depending on the location and purpose of use, the light from one or more light sources is intended to harmoniously illuminate the cover plate and to give a diffuse light impression. Alternatively, defined illumination of the environment of the vehicle or a light beam that is directed at a component of the interior is desired.
The prior art, U.S. Pat. No. 7,293,901 B2 describes an illumination element that has collimating optical elements and prismatic structures for beam deflection. Said collimating optical block is mounted in the luminaire. The light source provided is arranged at a distance of approximately 0.5 mm from the collimating unit, and therefore the notch depth of the prisms can be determined to approximately 0.15 mm.
EP 2500629 A1 discloses an illumination unit that has a closed housing. The light from the light-emitting means is emitted through the cover plate of the illumination unit. An optical film is applied on the inside of the cover plate. The optical film has either prismatic microstructures or exhibits a microlens structure.
It is therefore the objective of the present application to provide an illumination unit that emits the light in the desired form, without the need to take complicated and costly measures.